I. Field of the Invention
This invention relates generally to ladder stabilizing apparatus of the type disclosed in U.S. patent application Ser. No. 07/280,124, filed Dec. 5, 1988, and entitled "LADDER STABILIZER", and more particularly to an improved locking arrangement for selectively allowing or inhibiting longitudinal sliding motion between two telescoping poles.
II. Discussion of the Prior Art
In our above-referenced patent application, we disclose ladder stabilizing apparatus for an extension-type ladder to prevent accidental tipping or sliding of the ladder and injury to a workman. That device includes a pair of telescopingly extensible and retractable tubular pole members which are individually connected at one end thereof to the side rails of the ladder by hinge blocks and hinge pins. A folding brace is disposed between the ladder rails and the uppermost one of the telescoping tubes to establish the extent of displacement between the ladder rails and the deployed stabilizing legs. In that arrangement, a cam lock is deployed between segments of the telescoping tubular pole members to facilitate adjustment of the length thereof. The most often used approach to a locking mechanism has been the rather old idea of providing apertures through the walls of the telescoping tubes allowing a locking pin to be inserted therethrough. However, when it is considered that the pole length needs to be substantially continuously adjustable to accommodate a variety of uneven terrain conditions which might be encountered when using ladders, the provision of parallel holes along the lengths of the telescoping tubular members at closely spaced locations would so drastically weaken the strength of the pole members that such an arrangement becomes impractical and dangerous.